When fasteners are to be installed in structures such as panels and the like, often grommets are permanently installed the holes to accommodate fasteners. The usual procedure is drill the hole oversize and countersink one end. The grommet comprises a head portion at one end of a hollow tube having an outer diameter sized to fit in the hole and an internal bore having a diameter sized to receive the fastener. The grommet is installed from one side of the structure until the head portion contacts the panel and the opposite end extends out of the countersunk end. The opposite end is then deformed so as to extend into the countersink, thus locking the grommet into the panel.
Grommet installation tooling has been adapted from blind nut installation equipment manufactured by HS Tooling Corporation, Gardena, Calif., U.S.A. The modified tooling comprises an anvil (the modification) that abuts the installed grommet head and a flaring die that is portioned on the open end at the countersink end of the hole in the structure. A power tool having a threaded shaft is inserted thru the anvil, through the grommet hole and threaded to the flaring die. The flaring die includes a cylindrical portion that is adapted to slidably engage the grommet hole and a chamfered portion matching the countersink end of in the panel. The die also includes a thread hole there through.
In operation, a grommet is installed in the hole. The anvil is portion on the head portion of the grommet and the flaring die on the opposite end. A threaded member connected to a power tool is passed through the anvil and threadably engaged to the die. The power tool (typically hydraulically actuated) is activated, thus causing the die to engage the end of the tube deforming it so as to engage the counter sink end in the panel. Note that to prevent rotation of the die, the die includes a hex shaped surface that can be griped by a pliers or the like. In addition, the tool can be manually operated by use of wrenches and the like.
While this tooling is capable of installing the grommet in the panel, there is often a problem of the die becoming stuck in the center of the tube portion of the tube. This requires that the installer pry the die out of the tube or use a soft face mallet to dislodge it. This is a time consuming operation. It can also damage the grommet requiring the grommet to be removed and replaced.
Therefore, it is a primary object of the invention to provide an improved installation tooling for grommets.
It is another primary object of the invention to provide an improvements to existing tooling for installing grommets.
It is a further object of the invention to provide improved tooling for installing grommets that eliminates the sticking of the die to the grommet upon the installation thereof.